In cellular communications systems, such as Code Division Multiple Access (CDMA) cellular communications systems, the base stations of the cells may use the same radio frequency for an up-link communication. Each base station broadcasts a pilot channel or signal, a synchronization channel, a paging channel and a traffic channel. The pilot signal may comprise a pseudo-random noise (PN) code signal. The pilot signal is commonly received by all mobile stations within the cell range and is used by the mobile station for identifying the presence of a cellular communication system, which may be a CDMA system. The pilot signal transmitted by each base station in the system uses the same PN code but with a different phase offset. The base stations are identified by using a unique starting phase or starting time for the PN sequences.
At the mobile station, the process of acquisition includes receiving RF signals, which includes receiving pilot, synchronization, paging, and traffic channels from all nearby base stations. The mobile station must identify all the pilot signals that are receivable and generally selects the base station with the strongest pilot channel. The online channel acquisition is a battery-power consuming operation. Thus valuable savings in battery power may be realized if the power consumption may be reduced.